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Title: Two-dimensional electron gas at the Ti-diffused BiFeO{sub 3}/SrTiO{sub 3} interface

Oxide heterostructures with the broken translational symmetry often trigger a two-dimensional quantum confinement and associated unique electronic properties that cannot be observed in bulk constituents. Particular interest is devoted to the formation of two-dimensional electron gas (2DEG) at heterointerfaces between two insulators, which offers a fertile ground for fabricating advanced electronic devices. Here, we combine atomic force microscopy, transmission electron microscopy, and atomistic first-principles calculations to demonstrate that the (100) BiFeO{sub 3}/SrTiO{sub 3} interface takes on a metallic nature and a 2DEG is generated at this interface. Our findings also reveal that the electronic reconstruction due to the polar discontinuity and the variation in valence state of Ti arising from diffusion of Ti cations in SrTiO{sub 3} to Fe sites of BiFeO{sub 3} are critical to the formation of 2DEG at the heterointerface.
Authors:
; ; ; ;  [1] ;  [1] ;  [2] ; ;  [3] ;  [1] ;  [4] ;  [4]
  1. Advanced Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan)
  2. (China)
  3. Department of Materials Science and Engineering, Virginia Tech, Blacksburg, Virginia 24061 (United States)
  4. (Japan)
Publication Date:
OSTI Identifier:
22486327
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 107; Journal Issue: 3; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ATOMIC FORCE MICROSCOPY; CATIONS; CONFINEMENT; ELECTRON GAS; ELECTRONIC EQUIPMENT; INTERFACES; OXIDES; STRONTIUM TITANATES; SYMMETRY; TRANSMISSION ELECTRON MICROSCOPY; TWO-DIMENSIONAL SYSTEMS; VALENCE